Method for stabilizing the gas flow in water-bearing natural gas deposits or reservoirs

ABSTRACT

The invention relates to a method for stabilizing the gas flow in water-bearing natural gas deposits or reservoirs which produce at least 50 l of water per 1000 m 3  (Vn) of extracted natural gas. According to the method, a dispersion comprising the following components is injected into the water-bearing rock: A) an organosilicon compound as the dispersed phase; B) a hydrophilic dispersion agent, which can be mixed with water, and, if needed, C) a dispersing additive.

FIELD OF THE INVENTION

The invention relates to a process for overcoming effects which hinderthe continuous gas flow to a water-bearing natural gas production wellor natural gas storage well.

DESCRIPTION OF THE RELATED ART

Natural gas fields and natural gas reservoirs are to be encountered innatural underground cavities of the rock and natural gas reservoirs arealso to be encountered in artificial cavities. Said rocks are, by theirorigin, either sedimentary rocks or evaporites. These rocks are neverdry, but are generally associated with stratum waters, possibly evenwith extended aquifers. Water in the form of saline solutions thereforeoccurs not only on sinking a well, but on cementing the casing and inthe production phase of oil and gas fields. The isolation ofwater-bearing zones during drilling and cementing and blocking the wateringress in production wells is necessary for economic reasons in orderto enable the technical implementation of drilling projects and to avoidor decrease the removal of extracted water which is associated with highcosts.

Gas fields or gas reservoirs in which the stratum pressure has alreadysunk markedly below the hydrostatic pressure constitute a special case.Stratum water can only penetrate into a well if the water saturation inthe vicinity of the well is high enough to ensure a continuous flow andthe water phase has sufficient expansion energy and/or is entrained bythe gas. Owing to the higher water saturation in the pore cavity, thepressure losses increase during flow of the gas phase and the flowpressure on the well bottom decreases, with the water column being ableto grow in the well. If the well flow pressure is no longer sufficient,a phase of discontinuous gas production with decreased flow ratesoccurs.

In the various process variants for sealing off water ingress into wellsand during cementation, generally, plugging substances are used, such ascements, swellable clays, epoxide resins having fiber additives, inparticular in the case of fissured rocks, gels, suspensions withadditives and finely divided silicon dioxide. Reducing the water ingressinto production wells can be effected by two methods, that is selectiveblocking and plugging.

To plug water ingresses, these must be delimitable, so that theremaining productive zones of the rock do not also suffer. Gels ofpolymeric solutions of polyacrylamide, copolymers and biopolymers canexert a plugging action, but silica gels are also mentioned in someapplications. The polymer solution is gelled by admixing orafter-flooding with crosslinking substances. Another possibility forexerting a plugging action is precipitations of inorganic salts ororganic polymers from aqueous or non-aqueous solvents.

For the selective blocking of the water ingresses over the entirethickness of the hydrocarbon-bearing strata, no precautions need to betaken to select the points of water ingress. Selective blocking isachieved by two process variants, namely by adsorption of hydrophilicpolymers or by making the rock surfaces hydrophobic.

The hydrophilic absorption strata increase the flow resistance for thewater which continues to flow, which flow resistance is frequentlyincreased by swelling of the absorption stratum. In contrast, for thehydrocarbon phase there is no significant decrease in the permeability.When the rock is made hydrophobic, the interfacial tension has apartially blocking action for the incoming water in the form of thecapillary counter pressure.

For the selective blocking, high-molecular-weight polymers based onpolyacrylamide (also in cationic form), copolymers, terpolymers andbiopolymers are generally used. For making the rock surfaceshydrophobic, silanes, inter alia, have also been tested.

For example, in the Derwent Abstract of SU 1315602, the use of a mixtureof tetrabutoxytitanium with a relatively small content oftetrabutoxysilane or tetraethoxysilane for plugging wells against waterinflux is described. Since these active compounds have low flash points,complex safety precautions are necessary. In the Derwent Abstract of SU1838587, the use of ethyl silicates for sealing oil wells and gas wellsagainst permeating water is described. In both cases, the gaspermeability is also greatly reduced.

The flow resistance must be sufficient to hinder the water at theentrance to the production well. However, the flow resistance cannot beincreased as desired, since the liquids injected for blocking must bedistributed in the rock to develop their blocking action and the gasmust subsequently flush clear its flow paths by displacing the excessunabsorbed treatment liquid. In particular, when the rock permeabilityis low, the flow resistance cannot be too high, because otherwise thetreatment liquid is not injectable and the gas is not able to penetratethe treatment ring.

SUMMARY OF THE INVENTION

The object was therefore to provide a composition which adsorbs to rocksurfaces, is readily distributed even in rocks of low permeability,builds up a long-lasting flow resistance for water, but does not hinderthe entry of gas by discharging the residual treatment liquid and in themost favorable case even decreases the frictional resistance for gas, sothat long-lasting stable gas production is the consequence. These andother objects are achieved by injecting into the water bearing rock adispersion containing an organosilicon compound as the disperse fractionin a hydrophilic, water-miscible dispersion medium.

The invention relates to a process for stabilizing the gas flow inwater-bearing natural gas wells and gas storage wells which deliver atleast 50 l of water per 1000 m³ (S.T.P.) of natural gas produced, inwhich a dispersion comprising the components

A) an organosilicon compound as disperse fraction,

B) hydrophilic water-miscible dispersion medium and, if appropriate,

C) a dispersant,

is injected into the water-bearing rock.

Preferably, the dispersion is injected by means of a well into thewater-bearing rock. In this case organosilicon compound (A) adsorbs tothe rock surface. Excess dispersion is preferably distributed in thevicinity of the well by subsequently forcing in gas. The gas used forthis purpose can be, for example, air, nitrogen or, preferably, naturalgas.

The dispersion is readily distributed in the rock of thenatural-gas-containing fields and is chemically inert to the rockspresent in the gas fields, the natural gas and the production equipment.

Owing to the selective absorption of organosilicon compound (A) and, ifappropriate, dispersant (C) to the rock surfaces, the dispersionintroduced into the pore cavity changes. The flow resistance in the rockfor water is greatly increased, and that for gas is reduced. The wateringress is therefore reduced and natural gas can flow better. Naturalgas scarcely dissolves in organosilicon compound (A) and, ifappropriate, dispersant (C) and can, if no excess dispersion blocks theflow paths, flow substantially unhindered to the production well. Owingto the surface-smoothing action of the adsorption stratum, thefrictional pressures for injected and produced gas are decreased. Thiscauses an increased production rate for natural gas at the well.

Since the excess dispersion, or its decomposition products, aredisplaced by gas into the surroundings of the well, no problems occurduring production from the well owing to high water saturation in therock of the surroundings.

In particular, the organosilicon compound (A) is thermally stable attemperatures of 70° C. and significantly above which frequently prevailin gas fields. The flow resistance for water in the rock remains highand the water seal is retained for a long period.

If water flows at high velocity in the rock of the gas fields, thenatural gas produced contains at least 50 l of water per 1000 m³ ofnatural gas produced. The process is particularly suitable for naturalgas wells and gas storage wells which deliver at least 100 l of water,in particular at least 500 l of water, per 1000 m³ of natural gasproduced.

Preferably, the organosilicon compound is an organopolysiloxane. Theorganopolysiloxane (A) is preferably made up of units of the generalformulae (I) to (VII)

R₃SiO_(½) (I), R₂SiO (II), RSiO_({fraction (3/2)}) (III),SiO_({fraction (4/2)}) (IV), R₂(R′O)SiO_(½) (V), R(R′O)SiO (VI),R′OSiO_({fraction (3/2)}) (VII),

where

R denotes monovalent hydrocarbon radicals having 1 to 18 carbon atoms,which are optionally substituted by halogen atoms, cyano, amino,alkylamino, quaternary ammonium, mercapto, epoxy, anhydrido,carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups,

R′ denotes monovalent hydrocarbon radicals having 1 to 30 carbon atomsand hydrogen atoms, which are optionally substituted by halogen atoms,cyano, amino, alkylamino, quaternary ammonium, mercapto, epoxy,anhydrido, carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups.

Examples of hydrocarbon radicals R and R′ are alkyl radicals, such asmethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl,n-pentyl, isopentyl, neopentyl and tert-pentyl; hexyl radicals, such asn-hexyl; heptyl radicals, such as n-heptyl;

octyl radicals, such as n-octyl and isooctyl radicals, such as2,2,4-trimethylpentyl; nonyl radicals, such as n-nonyl; decyl radicals,such as n-decyl; dodecyl radicals, such as n-dodecyl; octadecylradicals, such as n-octadecyl; alkenyl radicals, such as vinyl, allyland 5-hexene-1-yl; cycloalkyl radicals, such as cyclopentyl, cyclohexyl,cycloheptyl and methylcyclohexyl; aryl radicals, such as phenyl,naphthyl, anthryl and phenanthryl; alkaryl radicals, such as o-, m-,p-tolyl, xylyl and ethylphenyl; aralkyl radicals, such as benzyl andalpha- and β-phenylethyl.

Examples of substituted radicals R and R′ are cyanoalkyl radicals, suchas β-cyanoethyl [sic], and hydrocarbon radicals which have beenhalogenated by fluorine, chlorine or bromine atoms, for examplehalo-alkyl radicals, such as 3,3,3-trifluoro-n-propyl,2,2,2,2′,2′,2′-hexafluoroisopropyl, 8 heptafluoroiso-propyl, andhaloaryl radicals, such as o-, m- and p-chlorophenyl.

Preferably, at least 90 mol % of the radicals R are methyl, ethyl orphenyl, in particular methyl.

Examples of polyoxyalkylene-substituted radicals R and R′ are theradicals of the general formula (VIII)

—R¹—[O(CR² ₂)_(c)]_(d)OR³  (VIII)

where

R¹ denotes a divalent C₁- to C₆-alkylene radical,

R² denotes hydrogen atoms, or monovalent C₁- to C₆-hydrocarbon radicals,

R² denotes hydrogen atoms, or monovalent C₁- to C₆-hydrocarbon radicals,

R³ denotes hydrogen atoms, monovalent C₁- to C₆-hydrocarbon radicals,C₁-C₈-acyl radicals, ethyl ether radicals or silyl radicals,

c denotes hydrogen atoms, monovalent C₁- to C₆-hydrocarbon radicals,C₁-C₈-acyl radicals, ethyl ether radicals or silyl radicals,

c denotes values 0, 1, 2, 3, 4 or 5, preferably 2 or 3 and

d denotes integers from 1 to 100, preferably 1 to 10.

Examples of the divalent radicals R¹ are saturated linear- orbranched-chain or cyclic alkylene radicals, such as methylene andethylene and propylene, butylene, pentylene, hexylene,2-methylpropylene, cyclohexylene, or unsaturated alkylene radicals suchas propenylene and hexenylene.

Examples of the monovalent radicals R² and R³ are listed under the aboveexamples for R and R′. Examples of acyl radicals are acetyl, of ethylether radicals tetrahydropyranyl, and of silyl radicals, trimethylsilyl.

Further examples of polyoxyalkylene-substituted radicals R and R′ arethe radicals of the general formula (IX)

—C—[O(CR²)_(c)]_(d)OR²  (IX),

HC—[O(CR² ₂)_(c)]_(d)OR²

where R², c and d have the meanings given above for the general formula(VIII).

Preferably, at most 20 mol % of the units of the organopolysiloxane (A)have the general formulae (V) to (VII).

Preferably, the organopolysiloxane (A) contains at least 50% by weight,in particular at least 80% by weight, of organopolysiloxanes (A1), whichconsist of at least 90 mol %, in particular 95 mol %, of units of thegeneral formula (II). In particular, reference is given to theorganopolysiloxane (A1) having an average viscosity of 5 to 2,000,000mPa·s, in particular 350 to 60,000 mPa·s at 25° C.

Preferably, the organopolysiloxane (A) contains at least 2% by weight,in particular at least 5% by weight, and preferably at most 70% byweight, of organopolysiloxane resins (A2) which consist of at least 90mol %, in particular 95 mol %, of units of the general formulae (I),(IV) and (V). The organopolysiloxane resins (A2) can, for example, besolid at room temperature and exhibit 0.25 [sic] to 1.25 units of thegeneral formula (I) per unit of the general formula (IV). Thesepreferred organo-polysiloxane resins (A2) can contain up to a total of5% by weight of Si-bonded alkoxy radicals or hydroxyl groups resultingfrom their preparation. The organopolysiloxane resins (A2) are generallynot completely miscible with polydimethylsiloxanes.

Although not cited in the general formulae (I) to (III), some of theradicals R can be replaced by hydrogen atoms directly bonded to siliconatoms. However, this is not preferred.

However, crosslinking organopolysiloxanes are also suitable. Thus, forexample, aqueous silicone dispersions which produce an elastomer afterremoval of the water can also be used.

Preferably, the organosilicon compound is also an organosilane. Theorganosilane (A) preferably has the above radicals R and OR′.Preferably, at least one radical R is present in the organosilane (A).

Preferably, the organosilane (A) has 1 or 2 radicals R and 2 or 3radicals OR′. Preferably, the radicals OR′ are C₁-C₆-alkoxy radicals, inparticular C₂- or C₃-alkoxy radicals. Preferably, the radicals R areunsubstituted or amino- or alkylamino-substituted C₁-C₁₂-alkyl radicals.

However, organosilicon compounds which spontaneously form a dispersionin the dispersion medium (B) without dispersants (C), so-calledself-dispersing organosilicon compounds, in particularorganopolysiloxanes, are also suitable.

Preferably, at least 10 parts by weight, in particular at least 50 partsby weight, of the hydrophilic water-miscible dispersion medium (B) arepreferably miscible with 100 parts by weight of water. As hydrophilicwater-miscible dispersion medium (B), preference is given to polarsubstances, for example aliphatic monohydric alcohols such as methanol,ethanol, n-propanol and i-propanol, glycols, ethers such as dioxane andtetrahydrofuran, dimethylformamide and, in particular, water.

Dispersants (C) which are suitable are a multiplicity of activecompounds which are expediently classified into surface-activedispersants, such as nonionic, anionic, cationic and ampholyticdispersants, into partially surface-active dispersants, such ashigh-molecular-weight substances and natural products, and intodispersants generally having low surface activity, such as inorganic andspecial dispersion aids. An overview is cited in Ullmanns Encyklopadieder technischen Chemie [Ullmanns Encyclopedia of Industrial Chemistry],Verlag Chemie Weinheim, 4th Edition 1975, Volume 10, pp. 449-473.

Preferably, the dispersant (C) is selected from the following dispersionaids below:

1. Alkyl sulfates, for example having a chain length of 8-18 C atoms,alkyl ether sulfates having 8-18 C atoms in the hydrophobic radical and1-40 ethylene oxide (EO) or propylene oxide (PO) units.

2. Sulfonates, e.g. alkyl sulfonates having 8-18 C atoms, alkylarylsulfonates having 8-18 C atoms, esters and half esters of sulfosuccinicacid with monohydric alcohols or alkylphenols having 4-15 C atoms; ifappropriate these alcohols or alkylphenols can also be ethoxylated with1-40 EO units.

3. Alkali metal salts and ammonium salts of carboxylic acids andpoly(alkylene glycol) ether carboxylic acids having 8-20 C atoms in thealkyl, aryl, alkaryl or aralkyl radical and 1-40 EO or PO units.

4. Partial phosphoric esters and their alkali metal salts and ammoniumsalts, e.g. alkyl and alkaryl phosphates having 8-20 C atoms in theorganic radical, alkylether phosphates or alkarylether phosphates having8-20 C atoms in the alkyl or alkaryl radical and 1-40 EO units.

5. Alkyl polyglycol ethers, preferably those having 2-40 EO units andalkyl radicals of 4-20 C atoms.

6. Alkylaryl polyglycol ethers having 2-40 EO units and 8-20 C atoms inthe alkyl and aryl radicals.

7. Ethylene oxide/propylene oxide (EO/PO) block copolymers having 8-40EO or PO units.

8. Fatty acid polyglycol esters having 6-24 C atoms and 2-40 EO units.

9. Fatty esters of glycerol, sorbitol and pentaerythritol.

10. Alkylpolyglycosides of the general formula R″—O—Z_(o), where R″denotes a linear or branched, saturated or unsaturated alkyl radicalhaving on average 8-24 C atoms and Z_(o) denotes an oligoglycosideradical having on average o=1-10 hexose or pentose units or mixturesthereof.

11. Polar-group-containing linear organopolysiloxanes having alkoxygroups and up to 24 C atoms and/or up to 40 EO and/or PO groups.

12. Salts of primary, secondary and tertiary fatty amines having 8-24 Catoms with acetic acid, sulfuric acid, hydrochloric acid and phosphoricacids.

13. Quaternary alkyl- and alkylbenzylammonium salts, whose alkyl groupshave 1-24 C atoms, in particular the halides, sulfates, phosphates,acetates and hydroxides.

14. Alkylpyridinium, alkylimidazolinium and alkyloxazolinium salts whosealkyl chain has up to 18 C atoms, especially in the form of theirhalides, sulfates, phosphates and acetates.

15. High-molecular-weight substances such as polymers, e.g. poly(vinylalcohol) and mixed polymers, such as vinylacetate/ethylene polymers.

16. Natural substances and their conversion products, such aspolysaccharides or cellulose and cellulose derivatives, such ascellulose ethers.

A dispersant, or else mixtures of a plurality of dispersants, can beused.

Dispersants which are particularly preferred are the dispersants listedabove under 1, 2, 3, 5, 6, 7 and 8, 12, 13, 15, 16, in particular thedispersants listed under 2, 3, 5, 6 and 13.

Preferably, 2.5 to 250, preferably 5 to 150, in particular 10 to 70,parts by weight of dispersant (B) are used per 100 parts by weight oforganosilicon compounds (A).

As additives (D)₁ the dispersion can contain, for example, fillers,fungicides, bactericides, algicides, biocides, odorants, corrosioninhibitors, native oils, thickeners, wetting agents, cosurfactants andorganic solvents.

The dispersions may contain small amounts of organic solvents resultingfrom the preparation. In particular in the case of the preparation oforganopolysiloxane resins, organic solvents or native oils arefrequently used. If the dispersion contains organic solvents, theircontent is preferably at most 50 parts by weight, in particular 5 to 20parts by weight, based on 100 parts by weight of organosilicon compounds(A).

The content of filler is preferably up to 20 parts by weight, inparticular 2 to 8 parts by weight per 100 parts by weight oforganosilicon compounds (A).

The preparation of the dispersions is known to those skilled in the art.

For the ready-to-use dispersion, the sum of the components organosiliconcompounds (A), dispersion medium (B), dispersants (C) and, ifappropriate, additives (D) is preferably 0.01 to 25% by weight,particularly preferably 0.05 to 10% by weight, in particular 0.1 to 2%by weight, based on the weight of the dispersion used.

The mean particle size of the dispersion is preferably at most 1000 mm,in particular 5 nm to 250 mm.

The compositions, particle sizes and concentrations of the dispersionscan be matched to the types of rock and conditions, such as temperatureand salt content, prevailing in the gas fields, so that the dispersionsare injectable even under extreme conditions. The particle size ispreferably selected in such a manner that the pore size of the rock isnot reached. By means of the high content of the componentsorganosilicon compounds (A), dispersion medium (B), dispersant (C) and,if appropriate, additives (D) in the dispersion, the dispersion mediumintroduced into the rock can be kept small. The concentration of thedispersion can be matched to rock properties, such as permeability anddepth of penetration. In the case of high permeabilities, smalleramounts of more coarsely disperse dispersions having higher contents ofthe components organosilicon compounds (A), dispersion medium (B),dispersant (C) and, if appropriate, additives (D) can be used. In thecase of low rock permeabilities, greater amounts of finely dispersedispersions having lower concentrations are used.

Substances are also suitable which do not form a organosilicon compound(A) in a dispersion medium (B) in which they were previously solubleuntil service conditions are achieved. Examples of these which may bementioned are glycol-functional silicone oils, which are soluble inpolar dispersion media such as water, but then, at elevatedtemperatures, reach a cloud point.

In the examples below, unless stated otherwise,

a) all amounts are based on weight;

b) all pressures are 0.1013 MPa (absolute);

c) all temperatures are 20° C.

d) S.T.P.=(volume at) standard conditions (0° C., 0.1013 MPa)(absolute);

e) PV=pore volumes;

f) nitrogen was used as the gas.

EXAMPLES

The examples were carried out in the following manner in the timesequence specified:

A Hassler cell was charged with cores from dry Bentheimer sandstone ofdimensions length 0.1 m and diameter 0.03 m.

Nitrogen was passed through each core at a constant flow rate of 50 m/d.The differential pressure Δp_(g) between the core entry and core exitwas measured.

The gas permeability k_(g) was calculated using the Darcy equation forcompressible fluids (1): $\begin{matrix}{k_{g} = \frac{2Q_{g}\mu_{g}p_{o}L}{A\left( {p_{1}^{2} - p_{2}^{2}} \right)}} & (1)\end{matrix}$

in which

Q_(g) denotes the gas flow rate, μ_(g) denotes the gas viscosity, p₀denotes the atmospheric pressure 0.1013 MPa, L denotes the core length,A denotes the core cross-sectional area, p₁ denotes the injectionpressure and p₂ denotes the core exit pressure. The gas permeabilitiesk_(g) are listed below in Table III.

The core was then saturated with water under a reduced pressure of 0.002MPa in the desiccator, built into a Hassler cell and water was passedthrough it at a constant flow rate of 5 m/d. The differential pressureΔp_(w) between the core entry and core exit was measured.

The specific water permeabilities k_(w) were calculated using the Darcyequation for incompressible fluid (2); $\begin{matrix}{k_{w} = \frac{2Q_{w}\mu_{w}L}{A\left( {p_{1} - p_{2}} \right)}} & (2)\end{matrix}$

in which

Q_(w) denotes the water flow rate, μ_(w) denotes the water viscosity,and L, A, p₁ and p₂ have the meanings above. The specific waterpermeabilities k_(w) are listed below in Table III.

20 pore volumes of PV silicone emulsion were injected into the core. Thedifferential pressure Δp_(e) between the core entry and core exit wasmeasured. The resistance factor RF=Δp_(e)/Δp_(w) was calculated as ameasure of flow resistance and is given below in Table III.

20 pore volumes of water were injected into the core. The differentialpressure Δp_(wr) between the core entry and core exit was measured inthe presence of the emulsion as remaining phase. The residual resistancefactor RRF=Δp_(wr)/Δp_(w) was calculated as a measure of the residualflow resistance and is given below in Table III.

The 4 silicone emulsions described in more detail in Table I below werestudied in Example 1-4.

In parallel with these studies, the influence of the residual siliconeoil emulsions on the gas permeability was studied on the same cores andemulsion systems as in the Examples one and three for the resistancereactor water.

The dry cores characterized in Table IV were saturated with water undera vacuum of 0.002 MPa in the desiccator, fitted into a Hassler cell andwater was passed through them at a constant flow rate of 5 m/d. Thedifferential pressure between core entry and core exit was measured andthe water permeability was determined in accordance with equation (2) at100% water saturation. The water was then displaced with gas at a flowrate of 500 m/d until a residual water saturation between 10 and 15% ofthe pore volume was established. The displaced water phase was collectedand the residual water saturation was determined in accordance withequation (3) from the volume balance between the original amount ofwater and the displaced amount of water: $\begin{matrix}{{S_{wr} = \frac{V_{wi} - V_{wp}}{V_{wi}}},} & (3)\end{matrix}$

in which

V_(wi) denotes the water volume originally present in the core and

V_(wp) denotes the water volume produced.

The differential pressure between core entry and core exit was thendetermined at a flow rate of 50 m/d for gas and the gas permeability atresidual water saturation was calculated in accordance with formula (1).

The core was then flooded with 20 PV of silicone oil emulsion at a flowrate of 5 m/d and the silicone oil emulsion was displaced by gas at aflow rate of 500 m/d until a residual emulsion saturation between 10 and15% of the pore volume was established. The saturation was determined inthe same manner as in the displacement of water by gas in accordancewith equation (3).

The gas permeability of the treated core was then determined in the samemanner as that measured in the residual water saturation. In Table IV,the gas permeabilities for residual water and residual emulsionsaturation are compared. The relative, i.e. dimensionless, gaspermeability used here is the ratio of the gas permeability at residualwater or residual emulsion saturation to the specific gas permeabilityof the core. In contrast to the treatment results cited in theliterature, the gas permeability did not decrease but increased.

TABLE I Emulsifier system/ Dispersion SC in % Active compound cosolvent1 52.00 33% of an amino 5% diethylene glycol monobutyl ether functionalsilicone oil 13% trimethylnonylpolyglycol ether having of the formula x,with 6 EO units the amine number being 1% fatty alcohol polyglycol etherhaving 0.25, the viscosity a saturated alkyl group (C₁₆-C₁₈) and 25 200mm²/s and R = Me EO units Benzalkylammonium chloride as preservative 250.00 33% of an amino 5% diethylene glycol monobutyl ether functionalsilicone oil 11% isotridecyl polyglycol ether having 5 of the formula x,with EO units the amine number being 1% fatty alcohol polyglycol etherhaving 0.15, the viscosity a saturated alkyl group (C₁₆-C₁₈) and 25 5000mm²/s and R = OH EO units Benzalkylammonium chloride as preservative 339.00 35% of an end-capped 4% isotridecyl polyglycol ether having 10PDMS with a viscosity of EO units 12,500 mm²/s Kathon as preservative 441.00 35% of an end-capped 3% alkyl (C₁₄-C₁₅) sulfonate PDMS with aviscosity of 3% triethanolammonium alkyl (C₁₂-C₁₄) 12,500 mm²/s sulfateFormaldehyde as preservative

RSiMe₂O[SiMe₂O]_(m)[SiMeR′O]_(n)SiMe₂R,  Formula x:

where R′=(CH₂)₃NH—CH₂—CH₂—NH₂

The viscosities of the emulsions 1 to 4 having a content of siliconeactive compound (A) of 10% by weight are listed below in Table II. Theviscosities were measured at 25° C. and a shear rate of 11 s⁻¹. In thecase of the dilutions with distilled water used in the examples to aconcentration of silicone active compound (A) of 0.2% by weight, theviscosities are virtually identical to that of the water.

TABLE II Silicone emulsion Viscosity [mPa · s] 1 3.27 2 1.42 3 1.26 41.62

TABLE III Core material Bentheimer sandstone RF values at injected RFvalues at injected pore Example Gas per- Water pore volumes volumesSilicone Poros- meability permeability Silicone emulsion Water emulsionity k_(g) [μm²] k_(w)[μm²] 5 10 15 20 5 10 15 20 1 0.208 1.99 1.82 0.970.94 0.94 0.98 1.21 2.1 2.72 3.1 2 0.221 2.85 2.61 1.03 1.11 1.23 1.31.89 2.49 3.06 3.5 3 0.234 3.41 3.31 0.91 0.91 0.91 0.97 1.12 1.36 1.852.4 4 0.234 3.21 3.2 0.97 1 1.05 1.15 1.73 2.39 2.86 3.35

The RF values before the injection are by definition 1. During theafter-flooding phase with water, the RRF values increase continuously.The increase in the RRF values has not ended after the addition of 20pore volumes of water. The dispersions build up a long-lasting flowresistance for water.

TABLE IV Benth. sands. Specific Residual Relative Residual RelativeSilicone Core gas per- water gas perme- emulsion gas emulsion material:meability saturation ability saturation permeabil- system Porosity kg(μm²) S_(wr) % % % ity 1 0.208 1.99 15 0.7 15 0.74 2 0.234 3.41 13 0.713 0.8 

What is claimed is:
 1. A process for stabilizing the gas flow in naturalgas wells and gas storage wells in water-bearing rock which deliver atleast 50 l of water per 1000 m³ of natural gas produced, measured atstandard temperature and pressure said process comprising injecting adispersion comprising the following components A) an organosiliconcompound as a disperse fraction, B) a hydrophilic water-miscibledispersion medium, and C) optionally a dispersant, into thewater-bearing rock.
 2. The process according to claim 1, in which theorganosilicon compound (A) is an organopolysiloxane comprising units ofthe general formulae (I) to (VII) R₃SiO_(½) (I), R₂SiO (II),RSiO_({fraction (3/2)}) (III), SiO_({fraction (4/2)}) (IV),R₂(R′O)SiO_(½) (V), R(R′O)SiO (VI), R′OSiO_({fraction (3/2)}) (VII),

where R denotes monovalent hydrocarbon radicals having 1 to 18 carbonatoms, which are optionally substituted by halogen atoms, cyano, amino,alkylamino, quarternary ammonium, mercapto, epoxy, anhydrido,carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups, R′ denotes hydrogen or monovalent hydrocarbonradicals having 1 to 30 carbon atoms optionally substituted by halogenatoms, cyano, amino, alkylamino, quarternary ammonium, mercapto, epoxy,anhydrido, carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups.
 3. The process according to claim 2, in whichthe hydrophilic water-miscible dispersion medium (B) comprises one ormore of aliphatic monoalcohols, glycols, ethers, dimethylformamide, andwater.
 4. The process according to claim 2, in which 5 to 150 parts byweight of dispersant (C) are used per 100 parts by weight oforganosilicon compound (A).
 5. The process according to claim 2, inwhich the dispersion is injected into the water-bearing rock by means ofa well, and excess dispersion is distributed in the vicinity of the wellby subsequently forcing in gas.
 6. The process according to claim 1, inwhich the hydrophilic water-miscible dispersion medium (B) comprises oneor more of aliphatic monoalcohols, glycols, ethers, dimethylformamide,and water.
 7. The process according to claim 6, in which 5 to 150 partsby weight of dispersant (C) are used per 100 parts by weight oforganosilicon compound (A).
 8. The process according to claim 1, inwhich 5 to 150 parts by weight of dispersant (C) are used per 100 partsby weight of organosilicon compound (A).
 9. The process according toclaim 8, in which 10-70 parts by weight of dispersant (C) are used per100 parts by weight of organosilicon compound (A).
 10. The processaccording to claim 1, in which the dispersion is injected into thewater-bearing rock by means of a well, and excess dispersion isdistributed in the vicinity of the well by subsequently forcing in gas.11. A process for stabilizing the gas flow in gas wells and gas storagewells in water-bearing rock which deliver at least 50 l of water per1000 m³ of natural gas produced, measured at standard temperature andpressure, said process comprising injecting a dispersion comprising thecomponents A) an organosilicon compound as a disperse fraction, B) ahydrophilic water-miscible dispersion medium, and C) optionally, adispersant, into the water-bearing rock, wherein said organosiliconcompound (A) is an organosilane which contains radicals R and OR′ whereR denotes monovalent hydrocarbon radicals having 1 to 18 carbon atoms,which are optionally substituted by halogen atoms, cyano, amino,alkylamino, quarternary ammonium, mercapto, epoxy, anhydrido,carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups, R′ denotes hydrogen or monovalent hydrocarbonradicals having 1 to 30 carbon atoms optionally substituted by halogenatoms, cyano, amino, alkylamino, quarternary ammonium, mercapto, epoxy,anhydrido, carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups.
 12. The process according to claim 11, in whichthe hydrophilic water-miscible dispersion medium (B) comprises one ormore of aliphatic monoalcohols, glycols, ethers, dimethylformamide andwater.
 13. The process according to claim 11, in which dispersants (C)comprise sulfonates, alkali metal salts of carboxylic acids, ammoniumsalts of carboxylic acids, alkyl polyglycol ethers, alkylaryl polyglycolethers, quarternary alkyl- and alkylbenzylammonium salts, and mixturesthereof.
 14. The process according to claim 11, in which 5 to 150 partsby weight of dispersant (C) are used per 100 parts by weight oforganosilicon compound (A).
 15. The process according to claim 11, inwhich the dispersion is injected into the water-bearing rock by means ofa well, and excess dispersion is distributed in the vicinity of the wellby subsequently forcing in gas.
 16. A process for stabilizing the seasflow in gas wells and gas storage wells in water-bearing rock whichdeliver at least 50 l of water per 1000 m³ of natural gas produced,measured at standard temperature and pressure, said process comprisinginjecting a dispersion comprising the components A) an organosiliconcompound as a disperse fraction, B) a hydrophilic water-miscibledispersion medium, and C) optionally, a dispersant, into thewater-bearing rock, wherein said dispersants (C) comprise sulfonates,alkali metal salts of carboxylic acids, ammonium salts of carboxylicacids, alkyl polyglycol ethers, alkylaryl polyglycol ethers, quarternaryalkyl- and alkylbenzylammonium salts, and mixtures thereof.
 17. Theprocess according to claim 16, in which 5 to 150 parts by weight ofdispersant (C) are used per 100 parts by weight of organosiliconcompound (A).
 18. A process for stabilizing the gas flow in gas wellsand gas storage wells in water-bearing rock which deliver at least 50 lof water per 1000 m³ of natural gas produced, measured at standardtemperature and pressure, said process comprising injecting a dispersioncomprising the components A) an organosilicon compound as a dispersefraction, B) a hydrophilic water-miscible dispersion medium, and C)optionally, a dispersant, into the water-bearing rock, wherein saidorganosilicon compound (A) is an organopolysiloxane comprising units ofthe general formulae (I) to (VII) R₃SiO_(½) (I), R₂SiO (II),RSiO_({fraction (3/2)}) (III), SiO_({fraction (4/2)}) (IV),R₂(R′O)SiO_(½) (V), R(R′O)SiO (VI), R′OSiO_({fraction (3/2)}) (VII),

where R denotes monovalent hydrocarbon radicals having 1 to 18 carbonatoms, which are optionally substituted by halogen atoms, cyano, amino,alkylamino, quarternary ammonium, mercapto, epoxy, anhydrido,carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups. R′ denotes hydrogen or monovalent hydrocarbonradicals having 1 to 30 carbon atoms optionally substituted by halogenatoms, cyano, amino, alkylamino, quarternary ammonium, mercapto, epoxy,anhydrido, carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups, further comprising an organosilane whichcontains radicals R and OR′, where R denotes monovalent hydrocarbonradicals having 1 to 18 carbon atoms, which are optionally substitutedby halogen atoms, cyano, amino, alkylamino, quarternary ammonium,mercapto, epoxy, anhydrido, carboxylato, sulfonato, sulfato,phosphonato, isocyanato or polyoxyalkylene groups, R′ denotes hydrogenor monovalent hydrocarbon radicals having 1 to 30 carbon atomsoptionally substituted by halogen atoms, cyano, amino, alkylamino,quarternary ammonium, mercapto, epoxy, anhydrido, carboxylato,sulfonato, sulfato, phosphonato, isocyanato or polyoxyalkylene groups.19. A process for stabilizing the gas flow in gas wells and gas storagewells in water-bearing rock which deliver at least 50 l of water per1000 m³ of natural gas produced, measured at standard temperature andpressure, said process comprising injecting a dispersion comprising thecomponents A) an organosilicon compound as a disperse fraction, B) ahydrophilic water-miscible dispersion medium, and C) optionally, adispersant, into the water-bearing rock, wherein said organosiliconcompound (A) is an organopolysiloxane comprising units of the generalformulae (I) to (VII) R₃SiO_(½) (I), R₂SiO (II), RSiO_({fraction (3/2)})(III), SiO_({fraction (4/2)}) (IV), R₂(R′O)SiO_(½) (V), R(R′O)SiO (VI),R′OSiO_({fraction (3/2)}) (VII),

where R denotes monovalent hydrocarbon radicals having 1 to 18 carbonatoms, which are optionally substituted by halogen atoms, cyano, amino,alkylamino, quarternary ammonium, mercapto, epoxy, anhydrido,carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups, R′ denotes hydrogen or monovalent hydrocarbonradicals having 1 to 30 carbon atoms optionally substituted by halogenatoms, cyano, amino, alkylamino, quarternary ammonium, mercapto, epoxyanhydrido, carboxylato, sulfonato, sulfato, phosphonato, isocyanato orpolyoxyalkylene groups, wherein said dispersants (C) comprisesulfonates, alkali metal salts of carboxylic acids, ammonium salts ofcarboxylic acids, alkyl polyglycol ethers, alkylaryl polyglycol ethers,quarternary alkyl- and alkylbenzylammonium salts, and mixtures thereof.20. A process for stabilizing the gas flow in gas wells and gas storagewells in water-bearing rock which deliver at least 50 l of water per1000 m³ of natural gas produced measured at standard temperature andpressure, said process comprising injecting a dispersion comprising thecomponents A) an organosilicon compound as a disperse fraction B) ahydrophilic water-miscible dispersion medium, and C) optionally, adispersant, into the water-bearing rock, wherein said hydrophilicwater-miscible dispersion medium (B) comprises one or more of aliphaticmonoalcohols, lycols ethers, dimethylformamide and water wherein saiddispersants (C) comprise sulfonates, alkali metal salts of carboxylicacids, ammonium salts of carboxylic acids, alkyl polyglycol ethers,alkylaryl polyglycol ethers, quarternary alkyl- and alkylbenzylammoniumsalts, and mixtures thereof.